Device for removing the burr of chain links

ABSTRACT

A burr-removing device for chain-welding machines has two knives located parallel to the plane of a C-shaped link and spaced to the extent of the link diameter, the knives being movable in their longitudinal direction for cutting off the weld ridge along the link circumference in two parallel tangential sectors, the device further having a fixedly held saddle upon which the link is held by two upsetting steels over its longitudinally extending portion, the device being particularly characterized in that the knives are movable perpendicularly to the longitudinal axis of the link.

United States Patent 1 swarm [72] Inventor Paul Esser Raderbergerstrasse I85, 5 Cologne- Raderberg, Germany [2i] Appl. No. 734,775 [22] Filed June 5,1968 [45] Patented June 29,197]

[54] DEVICE FOR REMOVING THE BURR OF CHAIN LINKS 3 Claims, 3 Drawing Figs.

[52] U.S. Cl 59/29 [51] lnt.Cl B2ll 15/00 [50] Field of Search 59/29, 34, 35

[56] References Cited UNITED STATES PATENTS 2,824,420 2/1958 Esser 59/29 3,070,952 1/1963 Wehlin 59/29 3,442,075 5/1969 Smerd 59/29 2125,96? 8/l938 Taylor. 59/35 3,096,6l2 7/1963 Coffey 59/22 Primary Examiner-Charles W, Lanham Assistant Examiner-Gene P. Crosby Atlorney-Richards & Gcier ABSTRACT: A burr-removing device for chain-welding machines has two knives located parallel to the plane of a C- shaped link and spaced to the extent of the link diameter, the knives being movable in their longitudinal direction for cutting off the weld ridge along the link circumference in two parallel tangential sectors, the device further having a fixedly held saddle upon which the link is held by two upsetting steels over its longitudinally extending portion, the device being particularly characterized in that the knives are movable perpendicularly to the longitudinal axis ofthe link.

PATENTEB JUN29 lsn 3.589.124

PAML [555R INVENTOR y raw AT'TJRNFY-5 DEVICE FOlR REMOVING THE BURR F CHAIN LINKS This invention relates to a device ofchain-welding machines for removing burr from chain links.

A prior art device of this type has two knives located paralle] to the link plane of a C-shaped chain link and spaced to the extent of the link diameter, the knives being movable in their longitudinal direction at an acute angle to the link axis, so that the weld burr is removed at the link surface along two parallel tangential planes. In this known device the link is held upright upon a saddle and is supported by upsetting steels which act upon the link curvatures from both sides and in an upwardly inclined direction at an acute angle to the longitudinal axis of the link. The knives and their common holder are movable toward and away from the weld ridge upon one of the upsetting steels under substantially the same angle as that of the steel This arrangement has various drawbacks. In the first place, the knives are located upon an upsetting steel which itself moves longitudinally, so that power transmission is difficult. Secondly, the play which is thus required between the knives and the link is comparatively large, also due to increased wear in the numerous links and guides, so that a clean out can be obtained only with difficulty, particularly since the knife is not guided sufficiently rigidly. In the third place, the knives must be moved by a wide length relatively to the upsetting steel and then moved back again, since the rest position must be outside the range of movement of the electrodes. Finally, when the links are of small size, the weld ridge section and the outer link curvatures of adjacent links are so close to each other that there is the danger that the knives will damage other links.

In another known burr-removing device, two parallel knives are used which can be moved parallel to each other toward the circumference of the link and which are interconnected by a knife holder; in this device the feed is not parallel but perpendicular to the link plane, so that the scraped off tangential sectors are located upon the inner or the outer side of the link portion which is to be welded. This construction, as compared to the initially described device, has the advantage that it can be connected directly to the machine frame and thus is independent from the upsetting steels, so that the operation can be more precise and the cut is cleaner; however, this device is not usable for a direct connection with a chain-welding machine, but must be always provided in a separate operating location outside the range of the electrodes. It has also the further drawback that the link must be held particularly carefully upon the saddle, since during the scraping, the pressure is transverse to the link plane and thus the link has the tendency to overturn. Furthermore, the remaining burr is pressed into the link by the pressure jaws, since they are operative in the same feed direction. If this is to be avoided, it is necessary to provide a further pair of knives movable parallel to the link plane.

Burr-removing devices are also known wherein one or two knives are moved over a link part in the longitudinal direction of the link. These devices have the advantage that the burr can be removed from the entire circumference in a single operation; however, they have the drawback that the sensitive knives are not shifted longitudinally but are subjected to bending, so that they break easily. Furthermore, a separate knife is required for each link diameter, while the prior art tangential cutting requires a single pair of knives, so that the distance between the knives can be adjusted to the link diameter. All processes which do not use tangential cutting have the drawback that the scraping tools are subjected to dangerously high loads and can break if the welding zone, after the welding, is cooled off through some disturbances or delays An object of the present inv. Alon is to overcome all these various difficulties.

Other objects will become apparent in the course of the following specification.

ln the accomplishment of the objectives of the present invention it was found desirable to provide a known tangential pair of knives the distance between which is adjustable and which can be shifted in the longitudinal direction; however, this pair of knives operates not only parallel to the link plane but at the same time also operates substantially perpendicularly to the longitudinal axis of the link; therefore, only a smaller volume portion of the burr is pressed in or the burr can be completely removed by further processes using other knives.

Since the device of the present invention does not require any special additional space it is advisable to combine this burr-removing operation with other processes and devices necessary to carry them out. By way of example, it is ad vantageous, after this preliminary burr removing, to provide a complete burr removal with two scratch knives having semicircular cutting edges corresponding to the link plane and which are also symmetrically movable toward each other; they either overlap each other, so that they must be shifted in the same direction, or they are located opposite each other with small play, so that they can be moved in opposite directions. Both arrangements are known. The last arrangement, as com' pared to the first one, has the advantage that shiftings of the link during final burr removal are eliminated; however, it has the drawback that there remain two opposed residual burr sections.

These known devices and burr-removing processes can obviously take place in the welding location itself, since there is enough room for locating these tools. However, the burr removal can also take place with a cold member at a special operational section.

In accordance with the present invention, the feed of the knives is toward the saddle and thus toward the link so that the link is firmly pressed upon the saddle without any side pres sure. This eliminates completely the edge formation, the turning, the tipping or the longitudinal shifting of the link upon the saddle. At the same time the link is automatically centered during the downward movement of the knives by knife cutters supported upon the circumference of the straight portion of the link, it it did not have the correct position with respect to the tipping direction. Furthermore, small differences in the alignment of the ends of the link are eliminated by guiding the pair of knives on both sides of the link and, to the same extend and at the same time, along the two link ends joined by the welding. Finally, the knives can be arranged without being subject to shakings and without difficulty between the two sets of electrodes and independently therefrom and from the upsetting steels, without requiring any additional space upon the electrode carriages or directly upon the machine frame, the knives being rigidly moved so that a clean cut is produced.

These various advantages of the device of the present invention can be further applied to the correct setting of the link by a special sequence of the movement of the knives. Namely, according to a further embodiment of the present invention, the knives are already located in their forward shifted position when the link is drawn in, and then the upper part of the link which is to be welded, is drawn through the knives and guided as the link is moved from the guiding rails to the saddle. This guiding procedure is particularly advantageous since initially the round portions of the link enter between the knives and during further movement the link is easily guided into its correct position. However, it is necessary for these setting requirements of the present invention that the knives be brought through an additional setting feed into the bottom position prior to the start of the link entry, whereupon the setting and the mounting of the upsetting steels take place, resulting in the correct position of the link upon the saddle, whereupon the knives must be withdrawn again so as not to influence the flow of the current. After completion of the welding operation, the knives must be shifted forwardly for the burr removal and at the same time they remain in the lowermost position when a further burr-removing or pressing operation is to take place at another location. If, on the other hand, it is desired that the removal of the burr residue take place directly at the welding location while maintaining the pressure of the upsetting steels, and this is the general rule, then the knives after completion of the cutting must be raised so that further scraping tools, or press steels, or the like can be moved to the welding location. In that case the knives are moved again to the forward feed location after completion of a pressing operation or a further burr removal; this can take place shortly after the treatment or, better still, after the finished link has been removed and a new link has been introduced in a similar manner.

It is not necessary to make any changes in the shape of the knives. The knife shafts can have sharp edges since the guiding procedure is secured by the round cross-sectional form of the link elements.

In accordance with the present invention, the knives have a new function of serving as an adjusting device and this provides two further possibilities of the development of the device of the present invention.

In the first place, an adjusting pin can be provided in the middle between the knives which is movable longitudinally relatively to the knives or their common knife holder and can be shifted by a spring, whereby the advanced position of the pin in the advanced position of the knives is so selected that the pin, by spring pressure, presses the link from above upon the saddle. The pin is preferably provided with a cone upon its free end so that when the link is being pulled in, it can serve for the yieldable guiding of the link and at the same time when the link has attained its final position it can continuously press it against the saddle, thereby supplementing pressure by the upsetting steels. This adjusting pin can also have the further task of indicating the wrong position or shape of the link, in that it can be connected with a switching off device of known type which is actuated when the link upon reaching its end position deviates from its prescribed form.

Similar feeling and switching devices have been used in prior art in chain-making machines but prior to the present invention they have not been used upon or in connection with burr-removing knives and they have not been located between sets of electrodes.

A second possibility of feeling and switching adjustments consists in that the link at the time it is introduced presses already against the corresponding side edge of the knife or upwardly against the setting pin due to an incorrect side shifting of its edges with respect to the rearwardly located edge and at its projecting edge. This produces pressure against the knife or the adjusting pin or the knife holder containing the two parts, the pressure being directed in the direction of movement of the link, and thus transversely to its shifting direction. This pressure by the use of usual small undamaging play can be used to actuate a switch, or it can be used to operate a switching device effecting transportation stoppage. In any case, a switch of this type will stop the machine, so that damages to the links and to the machine are avoided.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing, showing by way of example, a preferred embodiment of the inventive idea.

IN THE DRAWING FIG. 1 is a diagrammatic side view ofa device of the present invention, all unimportant parts having been eliminated.

FIG. 2 is an enlarged view of the right-hand portion of FIG. 1.

FIG. 3 is a front view of the device shown in FIG. 1.

FIG. 1 shows a saddle 5 having a groove 6 for receiving a link 7. As shown in FIG. 3, the link 7 is held upon its edge by two upsetting steels 8 which press it against the saddle. These steels engage the curvatures 9 of the link from above at an acute angle to the horizontal, while the bottom part 10 of the link rests in the saddle. The saddle, in addition to having a groove 6 for receiving the link, is also provided with inclined cuts 11 and 12 at the two edges to facilitate the insertion and the removal of the link. Adjoining links 13 show the manner in which a link chain is guided from left to right (looking in the direction of FIG. 3).

In accordance with the present invention a shaft 14 mounted in the machine frame carries a cam 15 which swings an angular lever 17 swingably mounted upon an axle 16. The short arm 18 of the lever 17 carries a roller 19 which engages the circumference 20 of the cam 15. The longer arm 21 of the lever 17 carries at its outer end a knife holder 22 (FIG, 2) which can be adjusted as to its height in the arm 21 and can be fixed by a setting screw 23 with a collar nut 24. The knife holder 22 carries two knives 25 which can be removed and replaced, and the positions of which-can be adjusted. The distance 26 between the sharp edges of the knives corresponds to the diameter of the link 9 and can be also adjusted. A setting pin 28 is carried by the knife holder 22 and is longitudinally movable therein. A spring 29 presses the pin 28 against the link. The upper end 30 of the pin is used to actuate a switch 31, the arrangement being such that the upper pin end 30 can engage and operate a switching pin 32 of the switch 31 so as to stop the machine.

As indicated in FIG. 3, the knives 25 are very narrow and find adequate space between the electrodes 33.

The operation of the device is apparent from the above description.

It is apparent that the described device is capable of many variations and modifications within the scope of the present invention.

What I claim is:

1. In a chain link welding machine, a burr-removing device comprising two knives spaced to the extend of a link and extending parallel to its plane, a fixed saddle, means moving said knives in their longitudinal direction for cutting off the weld ridge ofa link along the link circumference in two parallel tangential sectors and moving said knives perpendicularly to the longitudinal axis of the link, said means comprising a cam, a knife holder, a lever engaging said cam and carrying said knife holder, a pin located in said knife holder between the two knives and parallel thereto and a spring engaging said pin and adapted to press it against a link carried by the saddle; and two movable upsetting steels holding the link upon the saddle.

2. A device in accordance with claim 1, comprising a switching-off device for the machine, said switching-off device being actuated by said pin.

3. A device in accordance with claim 1, comprising a switching-off device for the machine, said switching-off device being carried by said knife holder. 

1. In a chain link welding machine, a burr-removing device comprising two knives spaced to the extend of a link and extending parallel to its plane, a fixed saddle, means moving said knives in their longitudinal direction for cutting off the weld ridge of a link along the link circumference in two parallel tangential sectors and moving said knives perpendicularly to the longitudinal axis of the link, said means comprising a cam, a knife holder, a lever engaging said cam and carrying said knife holder, a pin located in said knife holder between the two knives and parallel thereto and a spring engaging said pin and adapted to press it against a link carried by the saddle; and two movable upsetting steels holding the link upon the saddle.
 2. A device in accordance with claim 1, comprising a switching-off device for the machine, said switching-off device being actuated by said pin.
 3. A device in accordance with claim 1, comprising a switching-off device for the machine, said switching-off device being carried by said knife holder. 